The present invention relates to modular memory devices and that include non-volatile, solid-state memory arrays.
A variety of portable consumer products capture and store digital data in a non-volatile manner. Digital cameras and digital audio players are two examples of such products. The memory devices for this class of products are preferably modular devices that are small enough to be hand-held and easily transported by a user. Ideally, these storage devices should be removable and lightweight, and they should provide a multi-megabyte storage capacity and achieve a low actual sales price (ASP).
One prior-art approach to such memory devices is known as the flash memory card. Such cards fit into the palm of a user's hand, are lightweight, and provide storage capabilities that are matched to the needs of the portable device segment of the consumer market. However, flash memory cards do not adequately address the cost requirements of this market segment. The cost per megabyte as of June 2000 for flash memory cards, such as CompactFlash cards, is between $2-4 at the forty megabyte level (ASP). Since most consumer applications in the portable device segment of the market require at least forty megabytes of non-volatile storage, flash memory cards represent a significant portion of the cost of the overall device.
Other memory cards built to address this market segment include the Multi-Media Card (MMC), that has a cost per megabyte as of June 2000 of between $3-5 (ASP). All of these memory cards use conventional two-dimensional memory arrays.